Album des Pavillons 2000 [pay00] shows the normal national flag as the naval and state
ensign, not the national flag with the addition of a vertical blue stripe bearing the Naval Forces emblem at the hoist [shown below]. The use of the national flag as naval ensign is confirmed by photos of Saudi vessels in Janes and elsewhere.Joseph McMillan, 27 August 2006

Carr's Flags of the World [car61], pg. 244-245, says "the Ensign [is] the same as the National Flag, except [that] the Ensign has an additional charge in the form of a small white [fouled] anchor in the upper corner of the fly."Santiago Dotor, 15 April 2003

Album 2000 identifies this as the Navy flag, i.e. a flag representing the Naval Forces, but not the national flag as flown at sea.Joseph McMillan, 27 August 2006

Assuming that the legislation on the national flag also applies to this one (which it should do under Article 12), Article 1, Section 1.1 of Cabinet Decision 101 of 8 March 1973 (approved 15 March 1973) states that "the testament and sword shall...appear identical on both sides of the flag." Therefore, the sword hilt should always be to the observer's right, under the beginning of the shahada
(which reads from right to left) no matter which side the hoist is on. This last was confirmed by Mandatory Standards effective 3 November 1984.Christopher Southworth, 12 September 2003

So I understand that for the naval ensign [or, more probably, the RSNF Flag – Ed.], the blue stripe should be on the right – in the hoist, Arabic style.Gvido Pētersons, 15 September 2003

The answer is, "yes, it should." My own specification shows the panel and hoist on the left (and the sword's hilt towards the fly) in the Western tradition, but this is, in the Arabic tradition, the reverse of the flag. In the Arabic style of depicting the flag, the panel (and the hoist) would appear on the right, with the sword's hilt towards the hoist).Christopher Southworth, 15 September 2003

The Flags of all Nations chart
[reference uncertain – Ed.] shows the naval ensign as
the national flag with an additional blue vertical stripe at the
hoist with a yellow astrolabe centered on it. This stripe is
separated from the rest of the field by a white fimbriation.
Whitney Smith got the official contract to redesign the flags for the
Saudi Navy in the 1970's. He selected a gold astrolabe (as seen below
on the former jack) on green as the identifying
emblem of the Saudi Navy and designed a suite of flags for them.Nick Artimovich, 25-29 April 1996

Used from 1970s until late 1990's.Source:The World Encyclopaedia of flags [zna99]
The circular emblem is supposed to be a medieval Arab astrolabe, a navigational instrument that was a precursor of the modern sextant.Joseph McMillan, 17 March 2000